The ServiceProcessInstaller does work common to all services in an executable. It is used by the installation utility to write registry values associated with services you want to install.

To install a service, create a project installer class that inherits from Installer, and set the RunInstallerAttribute on the class to true. Within your project, instantiate one ServiceProcessInstaller instance per service application, and one ServiceInstaller instance for each service in the application. Finally, add the ServiceProcessInstaller instance and the ServiceInstaller instances to your project installer class.

When InstallUtil.exe runs, the utility looks for classes in the service assembly with the RunInstallerAttribute set to true. Add classes to the service assembly by adding them to the Installers collection associated with your project installer. If RunInstallerAttribute is false, the install utility ignores the project installer.

For an instance of ServiceProcessInstaller, properties you can modify include specifying that a service application run under an account other than the logged-on user. You can specify a particular Username and Password pair under which the service should run, or you can use Account to specify that the service run under the computer's System account, a local or network service account, or a user account.

Note

The computer's System account is not the same as the Administrator account.

An application's install routine maintains information automatically about the components already installed, using the project installer's Installer.Context. This state information is continuously updated as the ServiceProcessInstaller instance and each ServiceInstaller instance is installed by the utility. It is usually unnecessary for your code to modify this state information explicitly.

Instantiating a ServiceProcessInstaller causes the base class constructor, ComponentInstaller, to be called.

The following example creates a project installer called MyProjectInstaller, which inherits from Installer. It is assumed there is a service executable that contains two services, "Hello-World Service 1" and "Hello-World Service 2". Within the constructor for MyProjectInstaller (which would be called by the install utility), ServiceInstaller objects are created for each service, and a ServiceProcessInstaller is created for the executable. For the install utility to recognize MyProjectInstaller as a valid installer, the RunInstallerAttribute attribute is set to true.

Optional properties are set on the process installer and the service installers before the installers are added to the Installers collection. When the install utility accesses MyProjectInstaller, the objects added to the Installers collection through a call to InstallerCollection.Add will be installed in turn. During the process, the installer maintains state information indicating which objects have been installed, so each object can be backed out in turn in case of an installation failure.

Normally, you would not instantiate your project installer class explicitly. You would create it and add the RunInstallerAttribute, but the install utility actually calls, and therefore instantiates, the class.